Bearing Capacity of Soil MCQ with answer and solution

Concept

Net ultimate bearing capacity of clay soils

Formula

q_nu = c × N_c

Step-by-step solution

1. According to bearing capacity theory for cohesive soil (clay), net ultimate bearing capacity depends on cohesion and bearing capacity factors. 2. For footings in clay, the bearing capacity factor increases with the depth-to-width ratio, thereby increasing with depth. Answer: A

Explanation

According to Terzaghi and Skempton bearing capacity theories for purely cohesive clay soils, the net ultimate bearing capacity depends solely on the undrained shear strength of the clay. Because the capacity factor and cohesion product remain constant regardless of footing geometry, depth, or dimensions in pure clay, option A is the correct answer.

Why the other options are wrong

B) Net ultimate bearing capacity of clay depends on depth but is independent of footing size. D) Net ultimate bearing capacity of clay depends on depth rather than footing size.

Shortcut

For clay (purely cohesive soil), net ultimate bearing capacity (q_nu = c·Nc) is independent of footing size and depth.

Common mistake

Selecting option C or B by confusing net ultimate bearing capacity with gross ultimate bearing capacity, which depends on depth.